Polyacetylene latexes

Polyacetylene latexes (48) have been prepared by polymerizing acetylene in the presence of poly[(fert-butylstyrene)-fo-(ethylene oxide)]. The use of a tetrahydrofuran/cyclohexane (THF/cyclohexane) solvent combination led to the formation of a stable dispersion of nearly uniform spherical polyacetylene particles 40-200 nm in diameter. The block copolymer was separated from the polyacetylene by several wash cycles with a good solvent for the block copolymer (cyclohexane), and after removing the solvent, a polyacetylene powder was obtained. On the basis of nitrogen adsorption... 

When conducting the ROMP of norbornene or cyclooctadiene in miniemulsions [82], two approaches were followed (i) addition of a catalyst solution to a miniemulsion of the monomer and (ii) addition of the monomer to a miniemulsion of Grubbs catalyst in water. With the first approach it was possible to synthesize stable latexes with a high conversion, whereas for the second approach particles of >400 nm were created, without coagulum, but with 100% conversion. Subsequently, a water-soluble ruthenium carbene complex [poly(ethylene oxide)-based catalyst] was prepared and used in the direct miniemulsion ROMP of norbornene [83], whereby particles of 200-250 nm were produced. The catalytic polymerization of norbornene in direct miniemulsion was also carried out in the presence of an oil-soluble catalyst generated in situ, or with a water-soluble catalyst [84] the reaction was faster when using the oil-soluble catalyst. Helical-substituted polyacetylene could be efficiently polymerized in direct miniemulsion to yield a latex with particles that ranged between 60 and 400 nm in size, and which displayed an intense circular dichroism [85] that increased as the particle size decreased. The films were prepared from dried miniemulsion latexes that had been mixed with poly(vinyl alcohol) (PVA) in order to conserve the optical activity. 

The formation of a true copolymer was disputed as polyacetylene particulates suspended in solution by dissolved polymer, such as polystyrene, were also found to form stable latex particles [58]. In order to... 

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